SPURN POINT. 59 



that all geological works should be coloured upon one model ; but what 

 model shall we follow ? No geological map can possibly be so filled with 

 colours as to embrace all the minor subdivisions of rocks which, in local 

 sections, it would be unpardonable to omit. Besides, the colours of rocks 

 vary, and circumstances may make it desirable that sometimes a stratum 

 should be coloured strongly to mark its importance, though at other 

 times it would be better represented by a fainter shade. However, to 

 increase as little as possible the confusion of colours which already exists, 

 I have followed in the colours of the oolitic rocks the works of Mr. 

 Smith, and have preferred, with Mr. Greenough, to leave the chalk white. 

 Where rocks were to be thus represented for the first time, I have used 

 such colours as have not been before appropriated. 



The heights of the cliffs are represented above the level of high water 

 at spring tide, because this is, upon the whole, the most convenient line 

 that can be referred to ; and though it is too variable to serve for the 

 rigid determination of altitude by graduated instruments, it will be found 

 accurate enough for geological purposes. The tides rise on this coast 

 about fifteen or eighteen feet, and as they very generally lay up much 

 sand at the foot of the cliffs, and as at this level we commonly find much 

 debris accumulated, it seemed, upon the whole, better, except in a few 

 instances, to confine the colouring to the level of high water. It remains 

 to state that the following description is in every particular original ; and 

 was mostly executed on the spot. 



SPURN POINT, 



THE southernmost part of the coast of Yorkshire, is a low peninsula 

 of gravel and sand, accumulated by the sea and the wind, and laid in its 

 peculiar forms by the united action of currents from the sea and the 

 Humber. The materials which fall from the wasting cliffs between 

 Bridlington and Kilnsea, are sorted by the tide according to their weight 

 and magnitude ; the pebbles are strewed upon the shore, beneath the 

 precipice from which they fell ; the sand is driven along and accumu- 



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